Fat Soluble Vitamins

As the name suggests, these need fat to be absorbed into the
body. They may also be stored in adipose tissue if amounts consumed exceed
daily needs. They are not as readily excreted as water-soluble vitamins, which means they are not needed
on a daily basis (so long as your average intake meets requirements). However, they
are also much more potentially harmful if excessively large doses are taken for
prolonged periods.

Interactions/interfering
factors: Not enough sunlight exposure, living above the 40th
parallel, living in a polluted area, or having darker skin can impede the body?s ability to manufacture
cholecalciferol.

Water-Soluble Vitamins

Absorbed directly into the blood stream, vitamin C and the
B-complex vitamins circulate freely throughout the body, particularly the blood
and intracellular fluid. The kidneys detect and remove excess amounts in the
urine, and significant amounts are not stored in the body (with exception of
vitamins B6 and B12), so these vitamins are needed in more frequent doses, preferably every eight hours, and at least every few days.

Vitamin B1
(Thiamin)

Functions: Supports nervous
system function, participates in enzymatic energy release of carbohydrates,
crucial role in TCA cycle and glycolysis.

Interfering factors: Antibiotics, sulfa drugs and
oral contraceptives may decrease thiamin levels in the body. A high
carbohydrate diet or high alcohol intake increases the need for thiamin.
Consuming large amounts of tea and coffee (including decaffeinated), diuretics,
or eating raw freshwater fish or shellfish has been associated with thiamin
depletion. Athletes and pregnant women are also at increased need for thiamin.

Interfering factors: Oral
contraceptives, diuretics, and strenuous exercise can deplete the body of
riboflavin. Riboflavin is also easily destroyed by ultraviolet light, cooking,
antibiotics, and alcohol. Athletes, pregnant women, and anyone with a high
energy expenditure are at an increased need.

Toxicity: Rare, usually only due to large intake of
supplements as nicotinic acid. May causes skin flushing and nausea, possible
disturbed fat metabolism, possible early-onset of fatigue during exercise.

Interactions/interfering
factors: Relatively stable during cooking. There is an increased need for
athletes and pregnant women. Diuretics deplete the body of niacin.

Toxicity: Only when
supplemented at megadoses (200mg or more daily). Depression, fatigue,
irritability, headaches, nerve damage which is possibly irreversible. Unlike
most other B vitamins (with the exception of B12), it is stored in the body,
though in very small amounts.

Vitamin B12
(Cobalamin, cyanocoblamin)

Deficiencies: Usually only seen
in the elderly, and rarely in strict vegetarians. Pernicious, nerve degeneration,
paralysis, smooth tongue, fatigue, dementia, and depression. B12 is one of two
B vitamins (the other is B6) which is
readily stored in the body; stores may last up to three years before deficiency
symptoms appear.

Interfering factors: The
elderly may lack the intrinsic factor needed to absorb B12. Needs adequate folic acid in order to be activated in
the body. Inactive forms of the vitamin found in fermented foods such as soy
tempeh and some sea vegetables may actually inhibit metabolism and absorption
of usable B12.

Plant and Other Sources: Fortified cereals or other fortified foods, very small amounts in unwashed vegetables and fruits. Soy tempeh, miso, and
sea vegetables are not reliable sources, as the bioavailability of their B12 is
questionable. Bacteria in
the GI tract produce some B12, but the availability and absorbability of this
source is also questionable.

Folate (Folic
acid, folacin)

Functions:
Red blood cell formation, new cell division, protein metabolism, integral part
of spinal fluid, needed to activate vitamin B12 in the body. May reduce risk of
colon cancer, heart disease, and Alzheimer?s, and may alleviate depression and
anxiety.

Interfering factors: Losses of
up to ninety percent may occur during cooking. Supplementary folic acid is more
stable than folate found occurring naturally in foods. Pregnancy, physical
activity, injury, illness, stress, aluminum and magnesium antacids, and smoking
all deplete the body of folate. Many drugs, including anti-seizure agents,
beta-blockers, diuretics, and antibiotics interfere with absorption and
metabolism of folate. Needs vitamin B12
to be activated in the body.

Toxicity: Only possible at very large mega-doses of
supplements. May cause nausea, diarrhea, red blood cell damage, nosebleeds,
abdominal cramps. Possible iron
overload, may reduce blood levels of copper
and selenium. Abrupt cessation of
megadoses may lead to deficiency symptoms.

Interactions/interfering
factors: Aspirin, alcohol, analgesics, antidepressants, anticoagulants, oral
contraceptives and steroids may reduce levels of vitamin C. Smokers, those
under stress, and those living in polluted environments have an increased need
for vitamin C. Vitamin C is readily destroyed by heat, exposure to oxygen, and
exposure to alkaline (high pH or basic) solutions, and many food processing
techniques; therefore fruit juices from concentrate are poor sources. Calcium and magnesium ensure that not too much vitamin C is excreted.

Interactions/interfering
factors: Raw egg whites contain a protein (deactivated by cooking) which
destroys biotin. This is the only naturally known way of producing true biotin
deficiency, but athletes and diabetics may be at an increased need for biotin.